Delayed-acting blast valve operator construction

ABSTRACT

An arc-extinguishing unit is provided in a high-pressure gaseous environment having a pair of separable contacts, which when closed provide a primary blast valve, which prevents an exhausting flow of high-pressure gas through the interior of the contacts. Pneumatically connected with the interior of at least one of the separable contacts is a secondary blast valve, which is open in the closed-circuit position of the interrupting device. During the opening operation, upon separation of the separable contacts, the secondary blast valve begins to close, so that in the fully open-circuit position of the interrupter, the contacts will be separated, and the one or more secondary blast valves will be closed to prevent continued exhausting flow through the contacts from the high-pressure region externally of the contacts. The one or more secondary blast valves are mechanically latched in their open position, and a blast-valve activator, moving with the moving contact structure, compresses spring means tending to close the secondary blast valve, and additionally releases the latches at a predetermined point of time in the opening operation to thereby permit a delayed closing action of the secondary blast valve.

United States Reese et al.

" atent [451 May 23, 1972 [54] DELAYED-ACTING BLAST VALVE OPERATOR CONSTRUCTION Westinghouse Electric Corporation, Pittsburgh, Pa.

[73] Assignee:

[52] U.S. CI. ...200/l48, 200/148 B [51] Int. Cl. ..II01h 33/54 [58] Field of Search ..200/148, 148.2, 148 B [56] References Cited UNITED STATES PATENTS 2,824,937 2/1958 Strom ..200/148.2 2,949,521 8/1960 Schulz .....200/148.2 3,108,168 10/1963 Forwald ..200/148 B 3,439,140 4/1969 Frowein ..200/148 B FOREIGN PATENTS OR APPLICATIONS 1,209,641 1/1966 Germany ..200/148B 347,562 8/1960 Switzerland ..200/148B Primary ExaminerRobert S. Macon Attorney-A. T. Stratton, C. L. McI-Iale and W. R. Crout ABSTRACT An arc-extinguishing unit is provided in a high-pressure gaseous environment having a pair of separable contacts, which when closed provide a primary blast valve, which prevents an exhausting flow of high-pressure gas through the interior of the contacts. Pneumatically connected with the interior of at least one of the separable contacts is a secondary blast valve, which is open in the closed-circuit position of the interrupting device. During the opening operation, upon separation of the separable contacts, the secondary blast valve begins to close, so that in the fully open-circuit position of the interrupter, the contacts will be separated, and the one or more secondary blast valves will be closed to prevent continued exhausting flow through the contacts from the high-pressure region externally of the contacts.

The one or more secondary blast valves are mechanically latched in their open position, and a blast-valve activator, moving with the moving contact structure, compresses spring means tending to close the secondary blast valve, and additionally releases the latches at a predetermined point of time in the opening operation to thereby permit a delayed closing action of the secondary blast valve.

4 Claims, 1 1 Drawing Figures PRESSURE er GAS Fl G2,

HlGH PRESSURE F GAS PRESSURE 5P6 GAS HIGH PRESSURE SP GAS Patented May 23, 1972 3,665,133

.7 Sheets-Sheet 1 HIGH PRESSURE SP GAS Patented May 23, 1972 3,665,133

'7 Sheets-Sheet 2 PRESSURE SF6 GAS 45 HIGH PRESSURE F GAS LOW PRESSURE .SF5 GAS HIGH PRESSURE SF GAS Patented May 23, 1972 Sheets-Sheet I:

(230 PS 1) FOR EXAMPLE PRESSURE Patented May 23, 1972 3,665,133

7 Sheets-Sheet l PRESSURE SP5 GAS HIGH PRESSURE SF5 GAS Patented May 23, 1972 7 Sheets-Sheet 5 FIG.6.

WITNESSES INVENTORS Frank L. Reese and Hayes 0 DoKm,Jr

BY MM 'TORNEY Patented May 23, 1972 "7 Sheets-Sheet 6 FIG) Patented May 23, 1972 3,665,133

.7 Sheets-Sheet 7 FIG. IO.

- DELAYED-ACTING BLAST VALVE OPERATOR CONSTRUCTION CROSS-REFERENCES TO RELATED APPLICATIONS be made, is US. patent application filed Dec. 9, 1968, Ser.

No. 782,365, by (W.E. 39,242) by Richard E. Kane and Frank L. Reese, and likewise assigned to the assignee of the instant application.

BACKGROUND OF THE INVENTION The present invention is particularly concerned with a type of arc-extinguishing structure in which the separable contacts are closed in a high-pressure gaseous environment. The closing of the separable contacts forms a primary blast valve which prevents the exhausting of the high-pressure gas into the interior of one or both of the separable contacts. The manner of arc interruption is such that when the separable contacts are separated, during the opening operation, the high-pressure gas exhausts into the interior of one or both of the separable contacts. Situated downstream of the separable contacts is one or more secondary blast valves, which serve to control the exhausting of fluid flow through the interior of the separable contacts.

When the primaryblast valve is closed, or, in other words, when the separable contacts are closed, the secondary blast valve is open, thereby permitting a low-pressure region to occur interiorly of the separable contacts. During the opening operation, it is necessary to achieve very fast opening'of the separable contacts, and it may occur that even when the,

separable contacts are in their fully open-circuit position, an arc may still be in existence between the separable contacts. Upon such an occurrence, namely the are still being in existence, even when the separable contacts are in their fully open-circuit position, it is at this time necessary to continue the exhausting flow of high-pressure gas through the interior of the contacts to attempt to bring about interruption of such a continued arc.

For this reason, it is desirable to establish a delayed action of the secondary blast valves so that their travel curves are delayed with respect to the travel curve of the moving contact.

It is, therefore, necessary to provide a means for delaying the closing of the secondary blast valves during the opening operation to take care of such a condition, as set forth in the foregoing.

SUMMARY OF THE INVENTION According to the present invention, the secondary blast valves are mechanically latched in their open position, so that during the separable contact opening operation they are maintained open, and their closing travel curve is delayed with respect to the opening travel curve of the movable contact.

during the separable contact opening operation, the secondary blast valves will be unlatched, or released, and then moved toward their closed position, thereby halting any further exhausting of high-pressure gas through the contacts.

Accordingly, a general object of the present invention is to provide an improved secondary blast valve activator, which is associated with the movable contact structure, and serves to delay the closing movement of the secondary blast valves with respect to the opening movement of the movable contacts.

Still another object of the present invention is to provide an improved circuit interrupter of the type in which the contacts separate in a high-pressure gaseous environment, in which the contacts may move to their fully open position, and yet a continued exhausting flow of high-pressure gas may occur through the interior of at least one of the movable contacts to interrupt any are, which may continue to exist in the fully open-circuit position of the separable contact structure.

Still another object of the present invention is the provision of a reliable mechanism for delaying the closing travel of the secondary blast valves of an arc-extinguishing unit in which the separable contacts themselves form a primary blast valve.

Further objects and advantages will readily become apparent from reading the following specification taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a vertical cross-section through the circuit interrupter of the present invention, the contact structure being illustrated in the closed-circuit position;

FIG. 2 is a vertical sectional view, partly in side elevation, of the separable contact structure, the contacts being illustrated in the closed-circuit position;

FIG. 3 is a similar view illustrating the contact structure in the fully open-circuit position;

FIG. 4 is a vertical sectional view, partly in side elevation, of a modified-type of arc-extinguishing assemblage involving two serially related contact structures particularly adaptedfor the higher voltage ratings, the contacts being in the closed-circuit position;

' FIGS. 5, 6 and 7 illustrate details of the latching arrangement for the movable contact structure;

FIG. 8 is a plan view in section, taken substantially along the line VIII-VIII of FIG. 1;

FIG. 9 is a detailed view of an actuator arm;

FIGS. 10 and 11 are, respectively, end elevational and sectional views of the blast-valve activator.

DESCRIPTION OF THE PREFERRED EMBODIMENTS of the live parts. US. Pat. No. 2,757,261 describes the arcextinguishing characteristics of this particular gas 5.

Generally, the manner of operation of the circuit interrupter is the simultaneous actuation of the three valve control tripping rods 13, which extend upwardly into the top of the arc-extinguishing assemblages 15. Here the upper ends of the valve control tripping rods 13 are biased upwardly by a battery Of compression springs seating upon a spring seat affixed to a valve control rod, and serving to bias a pressure-balanced three-way control valve to its upper closed position. To effect an opening operation of the circuit breaker l, the valve control rod 13 is moved upwardly, say three-quarters of an inch, so as to permit the admission of high-pressure gas upwardly through a conduit and across the entire lower surface of a dual-acting piston structure, which is connected, by means of a piston rod, to the movable contact structure 20 of the interrupter l.

It will be observed that the piston structure is mechanically tied, by means of a piston rod, to a generally ladder-shaped structure 43, which comprises a pair of laterally spaced insulating operating rods 44, which extend axially of the arc-extinguishing assemblage 15 through a pair of hollow supporting tubes 45.

The region 47, immediately adjacent the contact structure 20, and externally thereof in the closed-circuit position thereof, as illustrated in FIG. 2, is at a relatively high pressure, say 230 p.s.i. as more clearly described in the US. Pat. application, filed Sept. I6, 1968 Ser. No. 759,992 by Lee E. Berkebile, the arc-extinguishing structure, or unit 24 being of the socalled downstream type, in which the high-pressure gas 5 moves into and through the separated contact structure 20, during the opening operation, until the flow of gas is halted by the closing operation of a pair of downstream, or secondary blast valves, indicated by the reference numerals 49 and 50in FIG. 2 of the drawings.

To effect an opening operation of the interrupter l, actuation of a three-way control valve 36 is brought about by upward movement of the valve-control tripping rod 13 to admit high-pressure gas upon the lower face of a piston structure I causing thereby opening upward motion of the contact structure 20.

MOVABLE CONTACT STRUCTURE 20 As briefly pointed out hereinbefore, the movable contact structure 20 comprises a generally H-shaped movable contact assemblage 43 secured at its upper end to a yokeshaped structure 74, which, in turn, is mechanically adjustably secured to the lower end of a piston rod. A pair of spaced insulating side operating rods 44, constituting a portion of said H- shaped structure 43, extend interiorly of hollow insulating supporting tubes 45, serving to space the interrupting units 24 axially apart.

With reference being directed particularly to FIG. 3 of the drawings, it will be observed that the yoke structure 74 has a downwardly extending stem portion 75, which is adjustably secured to a hollow movable contact 77. The side operating rods 43 additionally are secured to a movable blast valve activator 79 having a configuration more clearly shown in FIGS. 9-11 of the drawings.

The moving contact 77 makes separable engagement with a movable hollow seal structure 89 which is supported by a stationary hollow contact structure 83 (FIG. 2), which is fixably supported upwardly from a base support plate-port of 104. As shown in more detail in FIG. 3 of the drawings, an exhausting flow of arc-extinguishing fluid 5 at high-pressure'occurs across the are 85, and diametrically in opposite directions through the interior of both the movable and stationary hollow contacts 77, 83 as indicated by the arrows 86 in FIG. 3.

Generally, there is provided a primary blast valve 88 (FIG. 2) constituted by the lower tip portion 77a of the movable contact 77 making abutting engagement with a relatively stationary primary blast-valve seat 89 (FIG. 2) resiliently supported upon the stationary contact support 83, as shown in FIG. 2. A compression spring 91 provides a desired contact pressure therebetween, and provides for a limited amount of overtravel of the movable contact 77. Additionally, there is provided a plurality of circumferentially disposed stationary contact fingers 93, which make contacting engagement with the external side 77b of the movable tubular contact 77.

In addition to the primary blast-valve support, there is prowhich are closed near the end of the opening operation, as described more clearly hereinafter.

Depending upon the voltage range and current being interrupted, the improved circuit interrupter l of the present invention is adaptable to accommodate one or several arc-extinguishing units 24. FIG..2 illustrates an arrangement in which only a single pair of separable contacts 20 are provided. In the arrangement of FIG. 2, it will be noticed that there is provided a double exhausting flow of gas, inasmuch as both the stationary and movable contacts 77, 83 are hollow, and provide for exhaust outlets therethrough. However, for the higher voltage ratings, where a double break is desired, the construction,

as set forth in FIG. 4, may be provided. With reference to FIG. 4, it will be observed that there is provided a pair of serially related arc-extinguishing units 24. In the units 24 shown in FIG. 4, it will be observed that an exhausting flow occurs only through the pair of movable tubular contacts 77, the stationary contacts 81 being closed off, as at 81a. The pair of side operation rods 44 extend downwardly, as illustrated in FIG. 4, having an additional interconnecting yoke portion 95, which again has a downwardly depending stem 96 analogous to the stem illustrated at the upper end of FIG. 3 of the drawings. As a result, the pair of separable contact structures 20 in FIG. 4 are simultaneously actuated.

LATCI-IING STRUCTURE FOR THE SECONDAR BLAST VALVES 99 The circuit interrupter l of the present invention provides a novel means for operating the secondary blast valves 49, 50. On the circuit breaker of the present invention as previously pointed out, a gas-operated mechanism is used to open and close the contacts 20 of the interrupter 1.

The movable contact 77 of the interrupter form a seal with a relatively stationary primary blast valve seat 89 (FIG. 2)-coristituting a primary blast valve 88, so that when the breaker contacts 20 are closed, the seal 88 at the primary blast valve prevents the high-pressure gas from flowing into the center of one or both of the moving separable contacts 77, 81. At this time, the secondary blast valves 49, 50 are open. When the moving contact 77 opens, during the opening operation, the secondary blast valves 49, 50 are going closed to stop the exhausting gas flow into the low-pressure chambers 103,104 (FIG. 1).

In the circuit-interrupter construction as described, it is desirable that when the contacts 20 of the interrupter open, they arrive in the fully open-circuit position in the shortest period of time. The open position can be reached while there is still an arc between the contacts 77, 81. It is quite necessary that the secondary blast valves 49, 50 remain open at this time to allow gas flow to interrupt the are 85. Hence, the secondary blast-valve closing must have a travel curve, which is delayed from that of the moving'contacts 77 The following discussion deals with a means of delaying the secondary blastvalve travel.

With reference to FIGS. 2 and 3, it will be observed that the tubular moving contact 77 .is directly connected to the mechanism, and has a certain travel characteristic. The blastvalve activator 79 is also directly connected to the movable contacts 77, and has, consequently, the same travel. As the movable contact 77 moves to the open position, the blastvalve' activator 79 starts compressing a compression spring 105. This compression spring becomes loaded, since the opposite spring seat I06 is prevented from moving, since this spring seat 106 is a part of the secondary blast-valve device, and the blast valve is prevented from moving by two latches 107 (FIG. 7), which are spaced apart. There is some free movement of the activator 79 before starting to compress the compression spring 105, since it is necessary to keep the load on the operating mechanism to a minimum when starting the opening motion. After the activator 79 has moved a specific distance, and thereby compressed the spring 105, protrusions 108 on the activator 79 hit a raised surface 109 on the latches 107, thereby causing the latches 107 to move back, and allow the secondary blast valves 49, 50 to go closed, with a travel curve which is delayed as compared to that of the moving contact 77. When the secondary blast valve 49 is closed there is some compression on it due to the position of the activator 79 compressing the spring 105, additionally due to an inner spring inside blast valve biasing blast valve and basic mounting plate, plus a differential pressure holding it closed due to the geometry of the blast valve face.

When the circuit breaker contacts 77 are being closed, the secondary blast valves 49 and 50 are closed. The activator 79 with its rubber bumper lll strikes the secondary blast valve 49 and moves it to the open position. A small gas dashpot is also formed between the activator 79 and the blast valve 49 to help reduce the shock. At this time, the latches 107 fall under the shoulders 49a (FIG. 4) and the blast valve 49 is ready for another contact opening operation.

The pneumatic mechanism disposed within the cap structure 114 and concerning the dual action of the piston 8 is set forth and claimed in U.S. patent application, filed Dec. 10, 1968, Ser. No. 782,631 by William H. Fischer and Wayne S. Aspey and assigned to the assignee of the present invention.

The exhausting gas flow during the opening operation is collected in the low-pressure chambers 103, 104, and eventually is conducted by means of the hollow operating-rod tubes 17 down to a low-pressure tank at the base of a supporting framework as clearly illustrated in FIG. 1 of the drawings. A suitable compressor, not shown, is used to recompress the gas to the high pressure level of 220 psi, for example.

From the foregoing construction, it will be apparent that therehas been provided an improved latching and releasing arrangement to positively control the secondary blast valves in a circuit breaker of the type in which the primary blast valves are disposed adjacent the point of separation of the separable contacts, and an arc may be drawn while the separable contacts are in the open position. As a result, the closing action of the secondary blast valves may be delayed,- so that an adequate flow is assured for positive interruption of the arc, which may be drawn during the opening operation while the separable contacts are in the open position.

From the foregoing construction it will be observed that there is provided a positive camming releasing action on the part of the blast-valve activator. In addition, the compression spring 105, which is loaded during the opening operation of the movable contact structure carrying with it the blast valve activator, provides a desired closing force, so that when the secondary blast valves are released from their latched position, a high-speed closing operation of the secondary blast valve will be assured.

Although there has been illustrated and described specific structures, it is to be clearly understood that the same were merely for the purpose of illustration, and that changes and modifications may be made therein by those skilled in the art, without departing from the spirit and scope of the invention.

We claim:

1. A compressed-gas circuit interrupter comprising, in combination:

a. a pair of separable contacts at least one of which is tubular;

b. container means defining a high-pressure atmosphere about said separable contacts when they are in the closed-circuit position;

c. means defining a primary blast valve located closely adjacent the point of separation of the separable contacts and preventing the inward flow of said high-pressure atmosphere through the tubular separable contact when in the closed-circuit position;

d. means defining at least one downstream secondary blast valve independently movable from the movable tubular contact, and pneumatically connected to the region internally of said one tubular contact to halt the continued flow of compressed gas through the tubular contact when the circuit interrupter is in the open-circuit position;

e. means latching the secondary blast valve in the open position in the closed position of the interrupter;

' f. means opening said primary blast valve during the opening operation to enable a flow of high-pressure gas to flow into the interior of said one tubular contact; g. means holding the secondary blast valve open during the time of arcing; 5 b. means closing the secondary blast valve following a predetermined time delay; and,

i. releasing means movable with the movable contact structure to effect release of said latching means at a predetermined position in the opening operation to thereby effect closing of said secondary blast valve.

2. The compressed-gas circuit interrupter combination of claim 1, wherein both of the separable contacts are tubular and there are provided two downstream secondary blast valves.

3. A compressed-gas circuit interrupter comprising, in combination:

a. a pair of separable contacts at least one of which is tubular;

b. means defining a high-pressure atmosphere about said separable contacts when they are in the closed-circuit position;

c. a primary blast valve preventing the inward flow of said high-pressure atmosphere through the tubular separable contact when in the closed-circuit position;

d. at least one secondary blast valve pneumatically connected to the region internally of said one tubular contact to halt the continued flow of compressed gas through the tubular contact when the circuit interrupter is in the open-circuit position;

e. means latching the secondary blast valve in the open position;

f. spring means provided to tend to close the secondary blast valve; and,

g. releasing means for said latching means for compressing said spring means during the opening operation of the circuit interrupter.

4. A compressed-gas circuit interrupter comprising, in combination:

a. a stationary contact supporting a blast-valve seat;

b. a cooperable movable contact separable from the stationary contact to establish arcing and abutting said blastvalve seat;

. means defining a high-pressure atmosphere about said separable contacts when they are in the closed-circuit position;

. one of said separable contacts being tubular;

. a secondary blast valve pneumatically connected with the passage through said one separable contact which is tubular;

f. means for opening the secondary blast valve when the circuit interrupter is closed, and closing the secondary blast valve when the circuit interrupter is fully open;

g. means latching the secondary blast valve in the open position;

h. spring means provided to tend to close the secondary blast valve; and,

i. releasing means for said latching means compressing said spring means during the opening operation of the circuit interrupter.

6O a x: 

1. A compressed-gas circuit interrupter comprising, in combination: a. a pair of separable contacts at least one of which is tubular; b. container means defining a high-pressure atmosphere about said separable contacts when they are in the closed-circuit position; c. means defining a primary blast valve located closely adjacent the point of separation of the separable contacts and preventing the inward flow of said high-pressure atmosphere through the tubular separable contact when in the closedcircuit position; d. means defining at least one downstream secondary blast valve independently movable from the movable tubular contact, and pneumatically connected to the region internally of said one tubular contact to halt the continued flow of compressed gas through the tubular contact when the circuit interrupter is in the open-circuit position; e. means latching the secondary blast valve in the open position in the closed position of the interrupter; f. means opening said primary blast valve during the opening operation to enable a flow of high-pressure gas to flow into the interior of said one tubular contact; g. means holding the secondary blast valve open during the time of arcing; h. means closing the secondary blast valve following a predetermined time delay; and, i. releasing means movable with the movable contact structure to effect release of said latching means at a predetermined position in the opening operation to thereby effect closing of said secondary blast valve.
 2. The compressed-gas circuit interrupter combination of claim 1, wherein both of the separable contacts are tubular and there are provided two downstream secondary blast valves.
 3. A compressed-gas circuit interrupter comprising, in combination: a. a pair of separable contacts at least one of which is tubular; b. means defining a high-pressure atmosphere about said separable contacts when they are in the closed-circuit position; c. a primary blast valve preventing the inward flow of said high-pressure atmosphere through the tubular separable contact when in the closed-circuit position; d. at least one secondary blast valve pneumatically connected to the region internally of said one tubular contact to halt the continued flow of compressed gas through the tubular contact when the circuit interrupter is in the open-circuit position; e. means latching the secondary blast valve in the open position; f. spring means provided to tend to close the secondary blast valve; and, g. releasing means for said latching means for compressing said spring means during the opening operation of the circuit interrupter.
 4. A compressed-gas circuit interrupter comprising, in combination: a. a stationary contact supporting a blast-valve seat; b. a cooperable movable contact separable from the stationary contact to establish arcing and abutting said blast-valve seat; c. means defining a high-pressure atmosphere about said separable contacts when they are in the closed-circuit position; d. one of said separable contacts being tubular; e. a secondary blast valve pneumatically connected with the passage through said one separable contact which is tubular; f. means for opening the secondary blast valve when the circuit interrupter is closed, and closing the secondary blast valve when the circuit interrupter is fully open; g. means latching the secondary blast valve in the open position; h. spring means provided to tend to close the secondary blast valve; and, i. releasing means for saiD latching means compressing said spring means during the opening operation of the circuit interrupter. 